Buttonhole sewing machine



Jan. 2, 1934. J. PIKUL BUTTONHOLE SEWING MACHINE 5 Sheets- Sheet l Filed March 28,

lnvenTor. \Joseph Pi Kul b mwzf Jan. 2, 1934. J. PIKUL BUTTONHOLE SEWING MACHINE Filed March 26, 1931 5 Sheets-Sheet 2 lnvenToT". dosep-h Pi KUI byfuudsmdfld f ATTys.

Fig.5.

Jan. 2, 1934. J. PIKUL 1,941,620

I BUTTONHOLE SEWING MACHINE Filed March 26, 1931 5 Shyets-Sheet 3 Uoseph Pi Ku! byWMkW Aflys.

Jan. 2, 1934. P|KUL 1,941,620

BUTTONHOLE SEWING MACHINE Filed March 26, 1931 5 Sheets-Sheet 4 Is ,I

lnvenTor.

6| Joseph P'iK/gl 77/4: b MM AM? 2/ 63 ATTys.

Jan. 2, 1934. I L 1,941,620

BUTTONHOLE SEWING MACHINE Filed March 26, 1931 5 Sheets-Sheet 5 \nvenTor. Uoseph PiKul v {Q f Aflys.

Patented Jan. 2, 1934 1,941,620

UNITED STATES PATENT OFFICE BUTTONHOLE SEWING MACHINE Joseph Pikul, Troy, N. Y., assignorto The Reece r Button Hole Machine Company, Boston, Mesa, a corporation of Maine Application March 28, 1931. Serial No. 525.376

40 Claims. (Cl. 112252) This invention relates to buttonhole sewing buttonhole has been completed the parts are machines and particularly to the means for mashifted from stitching position to buttonhole-cutnipulating and controlling the under thread after ting position. v the sewing on the buttonhole has been completed In the embodiment of the invention herein in order that when the buttonhole cycle has been illustrated the means for drawing oil the meascompleted and the machine has been brought to ured length of underthread between the complerest the under thread may be left in such a position of the sewing on one buttonhole and the tion that the first stitches on the next buttonhole start of the sewing on the-next buttonhole is acwill be properly formed without leaving any procomplished in two stages. During the first stage J' end 0f e d t has 190 be u q e y a measured length oi under thread will be drawn trimmed. through the under thread tension which is pref- I accomplish this object by providing means erablyreleased for this purpose, and during the which becomes operative after the stitching on second stage the length of thread which has thus any buttonhole has been completed and the been drawn through the tensionis drawn through thread has been cut for drawing out a measured the sewing opening of the throat plate. By means 70 length of the thread end, which length provides of this construction an extra length oi thread the necessary amount of thread to enable the first will be drawn through the throat so that when stitch on the next buttonhole to be properly the stitching on the next'buttonhole beginsthere f rm d w t u l av a y p i ti d that is p ojecting through the throat antample length has to be. trimmed subsequently. In other words, of under thread to ensure the correct formation after the buttonhole has been completed and the oi. the first stitch on the buttonhole but without throat has been disconnected from the sewn butleaving any extra length that .would require subtonhole a measured length of the loose end of the sequent trimming. i thread is provided at the sewing point, which In the present embodiment of my invention I 55 length is sufilcient to provide for forming the first h shown a construction in which the pulling stitch on the buttonhole without the necessity of of the under thread through the tension during h ldin r ppi t t d nd with ut l avthe first stage of the thread pulling-oil movement ns a y p ti end which t u qu y is accomplished by the relative movement oi the v be trimmedstitch-forming mechanism and work holding In buttonhole sewing machines or the type means by which the parts are carried from herein illustrated the under thread mechanism is stitching position to buttonhole-cutting. position.

usually carried by a rotary turret situated be- Th nd stage of the thread pulling-oi! opneath the w rk n which a at i s pp r nd eration results from the reverse rotary motion the th oat p e provided wi the sewi p of the turret which occurs between the com- 13 in throu w i the under thread and h pletion of the sewing on one buttonhole and the cord pass tcthe work- It is common else to beginning of the sewing on the next buttonhole. vide the turret with a tension device which acts In order m give an understanding of t m on the under F vention I have illustrated in the drawings a se- In the operation of these machines the turret lected embodiment thereof which will now be 96 40 is rotated in one direction when sewing around l the end oi'the buttonhole and between the comaz i fi g i i Wm be pletion of the sewing on one buttonhole and the ou n 1: 1 9" c a t nh beginning of the sewing on the next buttonhole 1 is pa 51 e View or bu to ole sewing machine embodying my invention;

the turret is given a reverse rotation to bring it v 13 back into a position for the start of the next, 215 fragmentary View showmg the turret 00 which carries the under thread mechanism and buttonhole.

Such buttonhole sewing machines are also the portion of the frame on which the turret is commonly constructed so that after the stitching mounted and 8150 illustrating the devices 0 Delhas been completed on any buttonhole the stitchfor i t w l t a P 8- fl operaforming mechanism and work-holding means will tion; 105 be given a relative movement to separate the Fig. 3 is a fragmentary plan view 01' the turret stitched buttonhole y from the stitch-forming with parts omitted and illustrating the two acmechanism and to bring said stitched buttonhole tuating arms by which the two-stage thread pullinto position to be operated on by the buttonhole ing-ofl operation is accomplished; L cutter. In other words, after the stitching on any Fig. i is a view similar to Fig. 3 but showing the second stage of the thread pulling-off operation;

Fig. 5 is an under side view of the bed. frame and a portion of the stitch frame;

Fig. 6 is a view of the turret and under thread mechanism and also shows the devices for performing the two thread pulling-off stages;

Fig. 'l is a side view of Fig.6 with parts omitted;

Figs. 8 and 9 are fragmentary plan views of a turret showing a form of throat plate by which the second pulling-off stage may be accomplished, the under thread mechanism being omitted from these figures;

Fig. 10 is an enlarged section through the throat on the line 10--10, Fig. 8;

Fig. 11 is a fragmentary view showing the initial operation of the pull-oil. arm for pulling the extra length of thread through the throat;

Fig. 12 is a detail view of one of the friction disks of the under thread tension;

Fig. 13 is a fragmentary planview showing the thread cutter for cutting the under thread and stay cord;

Fig. 14 is a view illustrating the means for operating the pull-off arms on the turret;

Fig. 15 illustrates the means for operating the second stage pull-off arm;

Fig. 16 shows the position of the throat and under thread and stay cord at the end of the sewing on the buttonhole;

Fig. 17 shows the position of the parts after the work has been moved from stitching to buttonhole-cutting position;

The buttonhole sewing machine herein illustrated has the usual work-holding means and stitch-forming mechanism. The work-holding means comprises clamp plates 1 on which the work is supported and work clamps 2 for clamping the work against the plates 1, these work clamps 2 being mounted on the pivoted clamp arms 3 as usual. The stitch-forming mechanism comprises the usual needle 4 operating from above the work and controlling the needle thread 5, and under thread mechanism which is carried by the usual turret-6 that is situated beneath the work.

The under thread mechanism herein illustrated is of the type which comprises two loopers 7 and 8 and their co-operating loop spreaders 9. The looper 8 is shown as a threaded looper, it carrying the under thread 10.

The turret 6 is also provided with the usual throat 11 that is formed with a sewing opening 12 through which the needle operates.

The means for operating the loopers are not illustrated herein as they form no part of the present invention.

The stitch-forming mechanism is mounted on a stitch frame 13 and in the type of sewing machine herein shown said stitch frame is mounted on a bed frame 14 carrying the work-holding means and the relative movement between the stitchforming mechanism and work-holding means necessary to form the buttonhole is provided by moving the stitch frame back and forth on the bed frame 14.

The stitch frame 13 is formed with the under portion 15 carrying suitable bearings 16 in which the turret 6 is rotatively mounted, the usual means being provided for rotating the turret while sewing around the end of the buttonhole. This usual means comprises a lever pivoted at 81 to the cam casing 25 that encloses the main cam 24 by which the operations of the machine are controlled. The lever 80 is actuated by this cam 24 and is connected by a link 82 to an arm 83 on a vertical rock shaft 84. This rock shaft 84 carries two segment gears 85, 86 which mesh with gears 87 and 88 by which the turret and the needle bar for the needle 4 are rotated.

The turret 6 is provided with the usual under thread tension 1'7 through which the under thread 10 passes, said thread being shown as passing over a guiding pin 18, thence through the tension 17 and thence through a guiding passage 19 in the turret 6, through a guide eye 77 at the end of a resilient take-up arm 78, thence to the threaded looper 8 and from the looper it extends through the sewing opening 12 of the throat 11, this being the construction usually found in buttonhole sewing machines of this type.

The buttonhole-cutting mechanism by which the buttonhole slit is out has the usual construction. It comprises two cutting elements 20 and 21, one situated beneath the work and the other above the work. The element 21, which is above the work, is carried by a cutter lever 22 pivoted to the stitch frame at 23 and controlled as to its operationby the main cam 24 which is located in the cam housing 25.

Buttonhole sewing machines of this type are so constructed that when the stitching on any buttonhole has been completed the stitch-forming mechanism comes to rest with the needle 4 raised as shown in Fig. 1 and thereafter the stitch-forming mechanism and work-holding means have a relative movement to separate the stitched buttonhole from the stitch-forming means and'to bring the stitched buttonhole and buttonhole cutters into proper relative position sothat the cutters when actuated will cut the buttonhole slit correctly. In the type of sewing machine herein illustrated this relative movement is secured by moving the stitch frame 13 toward the left Fig. 1, such movement separating the stitch-forming mechanism from the stitched buttonhole 88 and bringing the buttonhole-cutting elements 20 and 21 into a position over the stitched buttonhole, which, it will be understood, is retained by the stationary work-holding means.

During this movement of the stitch frame by which the parts are shifted from stitching posi tion to buttonhole-cutting position a length 48 a of under thread will be drawn through the sewing opening 12 of the throat plate because of the fact that said under thread is attached to the work 26 at the last stitch and the strain on the under thread will flex the resilient arm 78. When the thread is cut the resiliency of the arm 78 restores it to its normal position against the stop 98 and thereby pulls back through the sewing opening a portion of the length 48 of under thread that had been drawn out by the shifting of the stitch frame from stitching to buttonholecutting position. The amount of under thread which is thus left pulled through the throat plate would not be suflicient to invariably'ensure the proper formation of the first stitch on the next through the throat a measured length of under thread of the correct amount so that there will be projecting through the throat plate a sumcient length of under thread to enable the first stitch of the next buttonhole to be properly formed without the necessity of holding or gripping said thread and without leaving any projecting end which has to be subsequently trimmed.

For thus pulling off the under thread I have provided, as stated above, a thread-manipulating mechanism by which the desired added length is drawn through the throat in two stages. The first stage serves to draw the added length of under thread through the under thread tension 17 and the second stage serves to draw said length of thread through the sewing opening of the throat plate.

The device for pulling the thread through the tension device 17 comprises a pull-off arm 27 which is pivoted to the turret at 28 and which carries at its upper end an eye or loop 29 through which the portion of the under thread between the tension and the guide duct 19 passes. In other words, this loop 29 is situated between said duct 19 and the tension 17.

After the stitching on a buttonhole has been completed and while the stitch frame is moving from stitching position to buttonhole-cutting position, or from the full line position Fig. 1 into a position in which the needle occupies the dotted line position Fig. 1, the pull-off arm 27 is swung from the full to the dotted line position Fig. 6 and at the same time the tension 17 is released so that by this movement an extra length of under thread 10 will be drawn through the tension and around the guide pin as indicated by the dotted lines 10a in Fig. 3. The release of the tension 17 simultaneously with the operative movement of the arm 27, is secured by making said arm 27 with an extension or wing 30 having a cam surface 31.

This cam surface co-operates with a tension-. releasing pin 32 which extends axially through the stud 33 on which the tension 17 is mounted. This tension is of the usual construction comprising the friction disks 34 and a disk 35 bearing against them and backed by a tension spring 36. The stud 33 is slotted and the disk 35 is provided with the two openings 37 through which the two halves of the slotted stud extend. The pin 32 bears against the portion of the disk 35 between said openings.

When the pull-off arm 27 is swung backwardly into the dotted line position Fig. 6 thereby to pull off the length 10a of under thread, the wing 30 is swung upwardly thereby causing the cam surface 31 to act on the pin 32 and shift it longitudinally which will result in releasing the pressure of the tension disks on the thread.

This operation results from the movement of the stitch frame from stitching to buttonholecutting position.

The means herein shown for accomplishing this comprises an actuating arm 38 which is mounted on a block 39 pivoted at 40 to the portion 15 of the stitch frame, the end of the actuating arm 38 extending inwardly over a finger 41 that projects laterally from the pull-off arm 27. The actuating arm 38 normally occupies a position just above the finger 41 but during the movement of the stitch frame from stitching position to buttonhole-cutting position or from full to dotted line position Fig. 1 the block 39 is turned about its pivot 40 thus bringing the end 55of the actuating arm 38 into engagement with the finger 41 and giving the pull-off arm 27 its operative movement.

The pull-off arm 27 is acted on by a spring 91 which'normally holds it in its position shown in Fig. 2 with the portion 92 thereof resting against the side of the turret 6.

In order to give the block 39 its movement above described the bed frame 14 has depending therefrom and rigidly secured thereto an arm or bracket 42 which carries at its lower end a lateral projection or pin 43 that engages the under side of the block 39, said block being held in engagement with said pin by means of a spring 44. The block 39 is formed with a cam surface 45 which is adapted to ride over the pin 43 during the movement of the stitch frame from stitching position to buttonhole-cutting position and since the pin 43 is stationary this movement of the cam surface 45 over the pin will rock the block 39 about the pivot thereby depressing the front end 55 of the actuating finger 38 and actuating the pull-off lever 27.

After the length 10a of under thread has been pulled'ofi through the tension and before the buttonhole cycle is completed this length 10a. of thread is given up by the pull-off lever 27 and is pulled through the guide 19 and guide eye 77 and through the sewing opening 12 in the throat 11 so that it will project beyond the throat thereby affording an ample length of under thread to form properly the first stitches on the next buttonhole.

This second stage of the thread pulling-off operation is accomplished by the reverse rotation which is given to the turret 6 between the completion of the sewing on one buttonhole and the beginning of the sewing on the next buttonhole.

One device adapted to pull the length of thread 10a through the sewing opening of the throat plate is illustrated in Figs. 3, 4, 6, 7 and 11. The throat 11 is shown as provided in its upper face with a thread-receiving groove 46 which extends from the sewing opening 12 to the edge of the throat plate.

When the sewing on a buttonhole has been completed and the stitch-forming mechanism comes to rest the turret 6 has the position shown in Fig. 3 and when the stitch frame has its movement to carry the parts from stitching position to button-hole-cutting position and a length 48 of under ihread is pulled through the sewing opening 12 by such movement the under thread will drop into this groove 46 as shown in Figs. 3,

4, 6, 11 and 17. The stay cord 49, which is drawn 1'1 through the sewing opening by this movement of the stitch frame as indicated at 50, will, how- 7 second stage of the under thread pull-off opera- 1.-

tion by which the length 10:: of under thread is drawn through the throat plate comprises a pull-off arm 51 which is pivoted to the turret at 52 and which is formed at its upper end with a hook portion 53 adapted to engage the under thread closely adjacent the throat plate.

During the sewing operation this pull-off arm 51 occupies the full line position Fig. 6. During the operation of the pull-off arm 27 by which the length of thread 10a is drawn through the tension device the pull-off arm is moved slightly into the position shown in Fig. 11 in which the hooked portion 53 of said arm 51 embraces the under thread 10 and closes the open end of the slot 46 to retain the under thread in the slot.

During this movement the point of the hook passes between the pulled-out portion of the cord 49 and the portion 48 of the under thread 10 so that the hook 53 will engage the under thread only but 'ill leave the cord 49 undisturbed. the vertical separation of the under thread 10 and cord 49 which is the result of the under thread occupying the groove 46 allowing the hook to engage the under thread without engaging the cord 49. In other words, with this construction the cord will be held out of the way of the hook 53. This initial movement of the hook 53 occurs during the movement of the stitch frame from sewing position to buttonhole-cutting position. Subsequently, the turret is given its reverse turning movement above referred to which results in swinging the arm 51 and hook 53 into the dotted line position Fig. 6 or the full line position Fig. 4 and at the same time the pull-off arm 27 is allowed to swing back into its full line positions Figs. 4 and 6. This combined movement results in drawing through the throat plate the length of under thread which was drawn through the tension by the pull-off arm 27 as seen in Fig. 4.

The block 39 has rigid therewith a second arm 54 that is provided on its under face with a cam portion 56.

The pull-off arm 51, which is normally acted on by a spring 57 that holds it in its full line position Fig. 6 has rigid therewith an extension 58 carrying an adjustable stop screw 59. This stop screw is so positioned that when the block 39 is moved into the position shown in Fig. 14 for the purpose of actuating the pull-off arm 2'7 the arm 54 will be brought into engagement with said screw 59 to an extent to cause a slight or initial movement of the pull-off arm 51 about its pivot 52, this initial movement being sufficient to carry the hook 53 into the position shown in Fig. 11.

During the reverse turning movement of the turret which occurs at the last part of the buttonhole cycle the stop screw 59 will wipe under the cam surface 56 thereby depressing the arm 58 and swinging the pull-01f arm 51 into the dotted line position Fig. 6. During this same turning movement of the turret the finger 41 passes.

out from under the extension of the arm 38 thereby allowing the pull-01f arm 27 to resume its full line position and give up a length 10a of under thread. The movement of the pull-off arm 51 into the dotted line position Fig. 6 draws this length of under thread through the throat as shown in Fig. 4.

After the extra length of under thread has thus been pulled oif through the sewing opening of the throat the under thread and stay cord are cut close to the work by means similar to that employed in my co-pending application Serial No. 525,092, filed March 25, 1931. This thread-cutting device comprises a thread cutter 60 mounted on a rock shaft 61 that is journalled in the bed frame. This cutter blade is formed with a cutting edge 62 and is provided with the work-positioning edge 63 which extends from the cutting edge 62 and is formed on substantially the arc of a circle struck from the rock shaft 61 as a center. The length of this edge 63 is such that when the cutter is in its inoperative'position shown in full lines Fig. 13 said edge will extend across and bridge the opening 64 between the work clamps through which the upper needle operates during the sewing of the buttonhole.

The parts are so designed that when the sewing on any buttonhole is completed and the stitchforming mechanism comes to rest the throat 11 will be directly underneath the work-positioning edge 63 as shown in Fig. 13 and hence when the stitch frame is moved from stitching position to buttonhole-cutting position the lengths 48 and 50 of under thread and stay cord which are drawn out through the throat will be drawn tightly around the edge 63 as seen best in Fig. 17. The strain on these threads serves to hold the stitched button hole in the position shown in Fig. 17 and to pull the work closely against the upper side of the cutting'knife 60.

After the threads have been thus pulled out the cutter 60 is moved from the full to the dotted line position Fig. 13 thereby to cut the threads between the cutting edge 62 and the edge 65 of one of the work clamps. During this swinging movement of the thread cutter the threads which are drawn around the edge 63 merely slide along said edge. The thread cutter is formed with the finger 66 which extends beyond the cutting edge .62 and which co-operates with the work-positioning edge 63 to guide ,the threads to the cutting edge 62.

The means for operating the cutter are such as are usually employed in sewing machines of this type. The shaft 61 has the arm 67 rigid therewith and this arm is adapted to be engaged by a pin 68 carried by a bar 69 that is situated beneath the bed frame and is guided at one end by the guiding screw 70 operating in a slot '71 in said bar. The baris connected to one end of a lever '72 pivoted to the bed frame at '73 and this lever has at its end a dog 74 adapted to be engaged and. actuated by a toe 75 connected to the lever as shown in Fig. 5. 76 is a spring normally holding the bar 69 in the position shown in Fig. 5.

When the lever 80 is actuated to give the turret its reverse turning movement the engagement of the toe 75 with the dog 74 will operate the lever '72 and thereby actuate the thread cutter 60.

The above-described operation, of manipulating the under thread so as to provide the measured length which projects through the throat occurs before the under thread and stay cord are cut by the under thread cutter 60 and hence when the thread is out there will be this added length of thread projecting through the throat plate which provides sufficient length of under thread to ensure the proper formation of the first stitch without the necessity of having any means for gripping or holding the under thread. The length of the loose end of under thread projecting through the throat which is thus provided is not only sufficient to ensure the proper formation of the first stitch on the buttonhole but is also a proper amount so that this Stitch may be formed tly without leaving any projecting end which has to be subsequently trimmed.

The invention, therefore, results in a simplification of the buttonhole sewing machine in that the devices for gripping the under thread to hold it after the stitching on one buttonhole has been completed and until the next buttonhole has started may be done away with together with the mechanism for operating such gripping devices.

Another construction by which the second stage thread-pulling operation may be carried out is illustrated in Figs. 8 and 9. In this em-- bodiment of the invention the throat, which is indicated at 61, .is provided with an extension 62 forming v mechanism which has a thread-receiving groove 63 in its edge.

When the stitch-forming mechanism comes to rest the. turret is in the position shown in Fig. 8 and as stated above when the stitch frame moves from stitching to buttonhole-cutting position' the under thread 10 will be drawn into the thread-receiving slot 46. When the turret has its reverse movement it will turn in the direction of the arrow from the position shown in Fig. 8 to that shown in Fig. 9 and during this turning movement the extension 62 will engage the under thread between the point 64 where it is attached to the work, which would be at the location of the last stitch of the buttonhole, and the sewing opening 12.

The result of 1 this operation will be to draw the extra length of thread through the sewing openingv and around the extensions 62 thus pulling the desired added length of thread through the sewing opening. When, therefore, the under thread is cut by the thread cutter there will be ample thread projecting through the sewing opening to form the first stitches.

I claim: i I

1. In a'buttonhole sewing machine, the combination with work-holding means, of stitch forming mechanism, a throat through which the under thread and stay cord are led to the work, means operative at the end of the sewing on a buttonhole to cut the under thread and stay cord, and means to present at the sewing point for the stitching on the next buttonhole a loose end of a stay cord projecting through the throat, and a loose end of under thread also projecting through the throat but of greater length than the loose end of cord and correctly measured to form the first stitch on the next buttonhole without leaving any projecting end that requires to be subsequently trimmed.

2. In a buttonhole sewing machine, the combination with workholding means, of stitchforming mechanism, a throat through which the under threadand stay cord are led to the work, means operative at the end of the sewing on a buttonhole to cut the under thread and stay cord, and means operative before the under thread and stay cord are cut to pull through the throat plate a length of stay cord andalso a length of under thread greater than said length of stay cord and correctly measured to form properly the first stitch on the next buttonhole without being held and without leaving any projecting end to be subsequently trimmed.

3. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism and provided with a throat through which the under thread is led to the work, a tension for the under thread on the turret, and means rendered operative at the end of the sewing on a buttonhole and acting on the under thread between the tension and the throat plate to draw off a length of thread from the source of supply, and means mountedon the turret and operating subsequently to draw said length of thread through the throat plate.

4. In a buttonhole sewing machine, the combination with work-holding means, of stitchrendered operative at the end of the sewing on a buttonhole and acting on the under thread between the tension and the throat plate to draw ofi a length of thread from the source of supply, means mounted on the turret and operating subsequently to draw said length of thread through the throat plate, and means to cut the thread close to the work.

5. In a buttonhole sewing machine, the combination with work-holding means, of stitch-forming mechanism including under thread mechanism, a turret carrying said under thread mechanism and. provided with a throat through which the under thread is led to the work, a tension for the under thread on the turret, means rendered operative at the end of the sewing on a buttonhole and acting on the under thread between the tensioned and the throat plate to draw off a length of thread from the source of supply, means to release the tension while the under thread is thus being drawn out, and means mounted on the turret and operating subsequently to draw. said length of thread through the throat plate.

6. In a buttonhole sewing machine, the combination with work-holding means, of stitch-forming mechanism including under thread mechanism, a turret on which the under thread mechanism is mounted, a throat plate carried by the turret through which the under thread is led to the work, a tension for the under thread, two pullof! levers pivoted on the turret, one acting on the under thread between the tension and the throat plate and the other acting on the under thread after it leaves the throat plate, and means to operate said pull-off levers successively.

7. In a buttonhole sewing machine, the combination with work-holding means, of. stitchforming mechanism including under thread mechanism, a turret on which the under thread mechanism is mounted, a throat plate carried by the turret through which the'under thread is led to the work, a tension for the under thread, two pull-01f levers pivoted on the turret, one acting on the under thread between the tension and the throat plate and the other acting on the unincluding under thread mechanism, a turret on which the under thread mechanism is mounted, a throat'plate carried by the turret through which the under thread is led to the Work, a tension for the under thread, two pull-off levers pivoted on the turret, one acting on the under thread between the tension and the throat plate and the other acting on the under thread after it leaves the throat plate; means to operate the first-named pull-01f lever to draw a length of thread from the source of supply through the tension, means to operate the second-named pull-off device subsequently thereby to draw said extra length of thread through the throat plate, and means to cut the under thread.

9. In a buttonhole sewing machine, the comat eiii-iig "through-whichthe under thread is led to the work, means to move the work-holding means and stitch-forming mechanism relatively after the completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means actuated by said relative movement to draw off a length of under thread from the source of supply on the supply side of the throat, and means operative subsequently and independently of said relative movement to draw said length of thread through said throat plate.

10. In a buttonhole sewing machine, the combination of work-holding means, of stitchforming mechanism including under thread mechanism, a rotary turret on which said under thread mechanism is mounted, a throat plate carried by said turret and through which the under thread is led to the work, a tension for the under thread on the turret, means to move the stitchforming mechanism and work-holding means relatively at the end of the sewing to separate the stitched buttonhole from the stitch-forming mechanism, means operated by said relative movement and acting on the under thread between the tension and throat plate to draw out a length of said thread, and means operated subsequently and independently of said relative movement to draw said length of thread through the throat plate.

11. In a buttonhole sewing machine, the combination with work-holding means, of stitchi'orming mechanism including under thread mechanism, a rotary turret on which said under thread mechanism is mounted, a throat plate carried by said turret and through which the under thread is led to the work, a tension for the under thread on the turret, means to move the stitch-forming mechanism and work-holding means relatively at the end of the sewing to separate the stitched buttonhole from the stitchforming mechanism, means operated by said relative movement and acting on the under thread between the tension and throat plate to draw out a length of said thread, means to release the tension while said thread is thus being drawn out, and means operating subsequently and independently of said relative movement to draw said length of thread through the throat plate.

12. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a rotary turret on which said under thread mechanism is mounted, a throat plate carried by the turret and through which the under thread is led to the work, means to produce a relative movement between the stitchforming mechanism and work-holding means at the end of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means to rotate the turret, means operated by said relative movement to draw out a length of under thread on the supply side of the throat plate, and means operated by the rotation of the turret to draw said length of thread through the throat plate.

13. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret on which said under thread mechanism is mounted, a throat plate carried by said turret and through which the under thread is led to the work, an under thread tension on said turret, means to produce a relative movement between the work-holding means and stitch-forming mechanism at the end of the sewing on the buttonhole thereby to separate the stitched buttonhole from the stitch-forming mechanism, means to rotate the turret, two pulloff levers pivotally mounted on said turret,,one acting on the under thread between the tension and the throat plate and the other acting on the under thread between the throat plate and the work, means to actuate one of said pull-off arms by said relative movement, means to operate the other of said pull-off arms by the rotary movement of the turret.

14. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism, a throat plate carried by the turret and through which the under thread is led to the work, means operative at the end of the sewing on a buttonhole to draw off a length of under thread on the supply side of the throat plate, and means to rotate the turret, said turret having an extension which engages the portion of the under thread extending between the turret and the work during the rotation of the turret and thereby draws said length of thread through the throat plate.

15. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret on which said under thread mechanism is mounted, a throat plate carried by the turret and through which the thread and stay cord are led to the work, said throat plate having a thread-receiving groove in its upper face, means to move the stitch-forming mechanism and work-holding means relatively at the end of the sewing on a buttonhole to draw a length of under thread and stay cord through the throat plate, the under thread dropping into said groove during this operation thereby becoming separated in a vertical direction from the stay cord, and means to engage the under thread between the throat plate and the work thereby to draw an added length of under thread through the throat plate.

16. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret on which said'under thread mechanism is mounted, a throat plate carried by the turret and through which the under thread and stay cord are led to the work, means to move the stitch-forming mechanism and work-holding means relatively at the end of the sewing operation on a buttonhole thereby to draw a length of under thread and stay cord through the throat plate, means for causing separation in a vertical direction of said stay cord and under thread during such relative movement, a pull-ofi arm pivoted to the turret and adapted to act on the under thread between the throat plate and the work, and means to actuate said arm to pull an added length of under thread through the throat plate, the vertical separation of the under thread and stay cord permitting the pull-oil? arm to engage the under thread without disturbing the cord.

17. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat through which the thread is led to the work, means operative at the end of the sewing on a buttonhole to draw of]? a length of under thread from the source of supply on the supply side of the throat, and means carried by the turret and operating subsequently to draw said length of thread through said throat.

18. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism and provided with a throat through which the under thread is led to the work, means carried by the turret and operative at the end of the sewing on a buttonhole and acting on the under thread on the supply side of the throat to draw oii a length of thread from the source of supply, and other means also mounted on the turret and operating subsequently to the firstnamed means to draw said length of thread through the throat.

19. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a turret carrying said under thread mechanism and provided with a throat through which the under thread is led to the work, means carried by the turretand operative at the end of the sewing on a buttonhole and acting on the under thread on the supply side of the throat to draw ofl" a length of thread from the source of supply, other means also mounted on the turret and operating subsequently to the first-named means to draw said length of thread through the throat, and means to cut the thread close to the work.

20. In a buttonhole sewing machine, the combination with work-holding means including a clamp plate against which the work is clamped, of stitch-forming mechanism including under thread mechanism, a turret carrying said under thread mechanism and provided with a throat through which the under thread is led to the work, means operative at the end of the sewing on the buttonhole and acting on the under thread on the supply side of the throat to draw off a length of thread from the source of supply, other means mounted on the turret and operating subsequently to the first-named means to draw said length of thread through the throat, and means operating above the clamp plate to cut the thread.

21. In a buttonhole sewing machine, the com-,

bination with work-holding means including a clamp plate against which the work is clamped, of stitch-forming mechanism ,including under thread mechanism, a turret carrying said'under thread mechanism and provided with a throat through which the under thread is led to the work, means carried by the turret and operative at the end of the sewing on a buttonhole and acting on the under thread on the supply side of said throat to draw oiT a length of thread from the source of supply, other means also mounted on the turret and operating subsequently to draw said length of thread through the throat, and a thread-cutting device operating between the clamp plate and the work.

22. In a buttonhole sewing machine, the combination with work-holding means,of stitch-forming mechanism including under thread mechanism, a turret carrying said under thread mechanism, a throat plate mounted on the turret and having an opening through which the under thread is led to the work, means to move the work-holding means and stitch-forming mechanism relatively after the completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means actuated by said relative movement to draw off a length of under thread from the source of supply on the supplylside of the throat plate, means operating subsequently and independently of said relative movement to draw said length of thread through said throat plate, and means to cut the thread close to the work.

23. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat through which the under thread is led to the work, means operative at the end of the sewing on a buttonhole to cut the under thread, and means operative before the thread is cut to first draw from the source of supply on the supply side of the throat a length of thread correctly measured to form the first stitch on the next buttonhole without leaving any projecting end that requires subsequently to be trimmed, and subsequently todraw said measured length through the throat.

24. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat through which'the under thread is led to the work, means .operative at the end of the sewing on a buttonhole to cut the under thread, and means mountedon the turret and operating before the thread is cut first to draw from the source of supply on the supply side of the throat a length of thread correctly measured to form the first stitch on the next buttonhole without leaving any projecting end that requires subsequently to be trimmed and subsequently to draw said measured .length through the throat.

25. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat plate having an opening through which the under thread and stay cord are led to the work, means to move the workholding means and stitch-forming mechanism relatively after the completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means to draw off a length of under thread from the source of supply on the supply side of the throat plate,

and other means operative subsequently and independently of said relative movement and acting on the under thread only to draw said length of thread through the throat plate.

26. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat plate having an opening through which the under thread is led to the work, means to move the work-holding means and stitch-forming mechanism relatively after the completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means to draw ofl a length of under thread from the source of supply on the supply side of the throat plate, other means operative subsequently and independently of said relative movement to draw said length of thread throughthe throat plate, and still other means operating independently from the lastnamed thread-pulling means to cut the thread close to the work.

27. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat plate through which the under thread and stay cord are led to the work, means operative at the end of the sewing operationto separate in a vertical direction the stay cord and the under thread, means operative on the under thread to pull through the throat plate without being held and without leaving any projecting end to be subsequently trimmed, and means to cut the thread and stay cord close to I the work.

28. In a buttonhole sewing machine, the com,- bination with work-holding means, of stitchforming mechanism, *a throat plate through which the under thread and stay cord are led to the work, means operative at the end of the buttonhole to pull'ofi a length of under thread from the source of supply on the supply side of the throat plate, means for causing a separation in a vertical direction of the stay cord and under thread on the work side of the throat plate, and means to engage the under thread on the work side of the throat plate after it has been separated vertically from the stay cord and pull said length of thread through the throat plate.

29. In a buttonhole sewing machine, tl e combination with work-holding means, of stitchforming mechanism, a throat plate through which the under thread and stay cord are led to the work, means operative at the end of the buttonhole to pull off a length of under thread from the source of supply on the supply side of the throat plate, a pull-off finger having a movement transversely to the direction of the length of thread extending from the throat plate to thework for pulling said length of thread through the throat plate, and means for causing a vertical separation of the under thread and cord by which the cord occupies a position out of the path,

of movement of said pull-off member.

30. In a buttonhole. sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat through which the under thread and stay cord are led to the work, means to move the stitch-forming mechanism and workholding means relatively at the end of the sewing operation on a buttonhole thereby to draw a length of under thread and stay cord through the throat, and means for causing a separation in a vertical direction of said length of stay cord and under thread during such relative movement.

31. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism including under thread mechanism, a throat through which the under thread and stay cord are led to the work, means to move the stitch-forming mechanism and work'- holding rrleans relatively at the end of the sewing operation on a buttonhole thereby to draw a length of under thread and stay cord through the throat, means to separate the under thread from the stay cord during such relative movement, and means acting on the separated under thread to pull an added length through the throat. I

32. In a buttonhole sewing machine, the combination with work-holding means, 'of stitchforming mechanism including under thread mechanism, a throat through which the under thread and stay cord are led to the work, means to move the stitch-forming mechanism and workholding means relatively at the end of the sewing operation on a buttonhole thereby to draw a length of under thread and stay cord through the throat, means to separate the under thread from' the stay cord during such relative movement, ineans acting on the separated under thread to pull an added length through the throat, and

. means operative at the end of the sewing operation to cause a separation of the lengths of stay cord and under thread extending between the throat and the work, and means operative on the under thread after such separation to pull a length thereof through the throat.

34. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, a throat through which the under thread and stay cord are led to the work, means operative at the end of the sewing operation to cause a separation in the vertical direction of the lengths of stay cord and under thread extending between the throat and the work, and means operative on the under thread after such separationto pull a length thereof through the throat.

35. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, a throat through which the under thread and stay cord are led to the work, means operative at the end of the sewing on a. buttonhole to cause a separation of the under thread and stay cord extending between the throat and the work, and a thread pull-ofi device operating in a direction at substantially right angles to the plane of the separated threads to engage the under, thread only and pull a length thereof through the throat.

36. In agbuttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, a throat through which the under thread and stay cord are led to the work, means operative at the end of the sewing on a buttonhole to cause a separation of the under under thread and stay cord are led to the work;

means operative at the end of the sewing operation to separate the portion of the under thread and stay cord leading from the throat to .the work,

and means operative on the under thread after such separation .to pull through the throat a length of under thread correctly measured to form properly the first stitch on the next button hole without being held and without leaving any projecting end to be subsequently trimmedand meansto cut the thread and stay cord.

38/In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, a throat through which the under thread and stay cord are led to the work, means operative at the end of the sewing operation to separate the portion of the under thread extending from the throat to the work from the stay cord, means situatedbeneath the work-holding means and acting on the separated under thread only to pull through the throat a length thereof correctly measured to form properly the first stitch on the next buttonhole. I

39. In a buttonhole sewing machine, the combination with work-holding means, of stitchforming mechanism, a throat plate having an opening through which the under thread and stay cord are led to the work, means to move the stitch-forming mechanism and work-holding means relatively after the completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, and to draw a length of under thread and stay cord through said throat plate, means to engage the thread only and draw an added length thereof through the throat plate, and means to cut the thread and stay cord.

40. In a buttonhole sewing machine, the combination with work-holding means including work-supporting plates, of stitch-forming mechanism including under thread mechanism, a throat ,plate having an opening through which the under thread is led to the work, means to move the work-holding means and stitch-forming mechanism relatively afterthe completion of the sewing on a buttonhole to separate the stitched buttonhole from the stitch-forming mechanism, means to draw oil a length of under thread from the source of supply on the supply side of the throat plate, other means situated beneath the work-supporting plates and operative subsequently and independently of the relative movement to draw said length of thread through the throat plate, and still other means to cut the thread close to the work.

JOSEPH PIKUL. 

